Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS4349824 A
Publication typeGrant
Application numberUS 06/192,742
Publication dateSep 14, 1982
Filing dateOct 1, 1980
Priority dateOct 1, 1980
Publication number06192742, 192742, US 4349824 A, US 4349824A, US-A-4349824, US4349824 A, US4349824A
InventorsEleanor S. Harris
Original AssigneeThe United States Of America As Represented By The Secretary Of The Navy
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Around-a-mast quadrifilar microstrip antenna
US 4349824 A
Abstract
A down link UHF antenna is designed which includes four equispaced arms ml plated at an angle on a fiberglass cylinder. A coaxial connector is connected to each of the four arms with the metal plated inner surface as the common ground.
Images(1)
Previous page
Next page
Claims(11)
What is claimed is:
1. An Around-A-Mast quadrifilar microstrip antenna for the periscope of a submarine which comprises:
a cylinder of a non-conductive material having metal plated at the top, bottom and inner surfaces thereof and forming a common ground plane from the top, bottom and inner surfaces;
a plurality of generally parallel conductive bands electrically isolated from said common ground plane on the outer surface of said cylinder;
connecting means for each member of said plurality of conductive bands on the outer surface of said cylinder; and
matching networks for delaying appropriately the outputs from each member of said plurality of conductive bands on the outer surface of said cylinder.
2. The antenna of claim 1 wherein said non-conductive material of said cylinder is fiberglass G-10.
3. The antenna of claim 2 wherein said plurality of generally parallel conductive bands include four generally parallel copper bands metal plated on the outer surface of said cylinder.
4. The antenna of claim 3 wherein said four generally parallel copper bands make an angle of 15 degrees with a plane perpendicular to the axis of said cylinder.
5. The antenna of claim 4 wherein said four generally parallel copper bands metal plated on the outer surface of said cylinder wrap around the outer surface of said cylinder so as to make the antenna right-hand circularly polarized.
6. The antenna of claim 4 wherein said four generally parallel copper bands metal plated on the outer surface of said cylinder wrap around the outer surface of said cylinder so as to make the antenna left-hand circularly polarized.
7. The antenna of claim 4 which further includes a radome around said cylinder for pressure proofing the antenna.
8. The antenna of claim 1 wherein the inner metal plated surface of said cylinder is used as a common ground terminal.
9. The antenna of claim 8 wherein said matching networks and the outputs from each of connecting means are fed through the inner volume of said cylinder and the antenna being an integral part of the mast of the periscope.
10. The antenna of claim 1 wherein said matching networks for delaying appropriately the outputs of each member of said plurality of conductive bands on the outer surface of said cylinder includes at least a pair of 180° phase shifters, one member of said pair being connected to a first set of two oppositely disposed conductive bands on the outer surface of said non-conductive cylinder and the second member of said pair of 180° phase shifters being connected to a second set of oppositely disposed conductive bands on the outer of said non-conductive cylinder.
11. The antenna of claim 10 which further includes at least a 90° phase shifter being connected between the outputs of said pair of 180° phase shifters in order to add the signals from said first and second sets of conductive bands on the outer surface of said non-conductive cylinder.
Description
BACKGROUND OF THE INVENTION

The present invention generally relates to antenna systems and more particularly to a down link antenna for communication satellites.

Common conventional radio frequency antennas are unsuitable for use in the mid section of the mast of a periscope for communicating with communication satellites. One of the problems in using such antennas is the large dimensions in the designated frequency range particularly when circular polarization is required. As an example, two cross dipoles used as an antenna for a periscope will have to be large in dimensions in the frequency range of 200-300 MHz and it will be difficult to integrate such an antenna in the mast of a periscope. Furthermore, the antenna should be virtually height independent with respect to the ground plane which is critical for mast-mounted submarine antennas. Furthermore, an antenna when mounted on a major periscope should provide reliable communication reception from satellite without raising of the dedicated satellite communication antenna mast. Thus, there is a need for an antenna to be used for a major periscope to provide reliable communication reception from satellites which has small enough size and also can be fitted into a periscope.

SUMMARY OF THE INVENTION

A down link antenna for communication satellites to be fitted on major periscopes is an arrangement which can be integrated in a periscope's mast and particularly into the area of its sleeve's dielectric spacer and feed. The antenna is a UHF (ultrahigh frequency) antenna with a center frequency of 250 megahertz (MHz) for use with communication satellites. It includes four equispaced arms, preferably each of one inch width and a nominal length of 3/4 λ (λ being the wave length of the signal), which are metal plated at an angle, preferably at an angle of 15 degrees, on a fiberglass cylinder. A coaxial connector is connected to each of the four arms with the metal plated inner surface as the common ground. Interior or the inner side of the fiberglass cylinder is also metal plated.

An object of subject invention is a UHF down link antenna which is extremely small in size to operate at the designated frequency.

Another object of subject invention is to have an antenna which may be used as a section in a cylindrical mast wherein cables, wave guides optic column, etc. are fed through the length of the antenna section, thus allowing the antenna to be integrated into the mast below existing sensors with no change to the feed systems of the sensors.

Still another object of subject invention is to have a down link UHF antenna which can be integrated into the mast of a periscope in the area of its sleeve's dielectric spacer and feed.

Still another object of subject invention is to have a UHF down link antenna which is virtually height independent with respect to the ground plane which is critical for the mast mounted submarine antennas.

Still another object of subject invention is to have an antenna which can be mounted on a major periscope to provide reliable communication reception from satellites without raising of the dedicated satellite communications antenna mast.

Still another object of subject invention is to have a UHF antenna for fitting periscopes which is mechanically sound particularly when G-10 fiberglass is used as the dielectric therefor.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the drawings when considered in conjunction with the accompanying drawings wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional view of the antenna built according to the teachings of subject invention;

FIG. 2 is top view of the antenna of FIG. 1;

FIG. 3 is a block diagram of the feed system used in the antenna of FIG. 1;

FIG. 4 is an overhead elevation pattern of a quadrifilar antenna in free space; and

FIG. 5 is an overhead elevation pattern for the antenna response over a ground plane with the antenna mounted in the mid section of the periscope mast.

DESCRIPTION OF A PREFERRED EMBODIMENT

Referring to the drawings, FIG. 1 shows a cross-sectional view of an electrical antenna built according to the teachings of subject invention. Antenna 10 includes a fiberglass cylinder 12 preferably made of G-10 fiberglass and having a dielectric constant ε and the cylinder is preferably 8 inches long and with an outside diameter of 7.25 inches and internal diameter of 4.5 inches. However, it should be well understood that these features of the cylinder or material can be varied without deviating from the teachings of subject invention. Fiberglass cylinder 12 is coated with metallic plating on the inside as well as at the top and bottom surfaces thereof. Cylinder 12 has four equispaced and generally parallel arms 18, 20, 22 and 24, preferably each arm being one inch wide. Arms 18, 20, 22 and 24 are metal plated at an angle, preferably making an angle of 15 degrees with a plane perpendicular to the axis of the cylinder 10 on the outer surface thereof. Each of the coaxial connectors 26, 28, 30 and 32 is connected to its respective arm in such a way that each of these connectors is attached to the plate of the interior ground connection acting as a ground connection and the central pin of each connector feeds its respective arm. The arms 18, 20, 22 and 24 may be fine tuned independently or in pairs to resonant length for desired frequency. A matching network for this model is 25 ohms, but it varies with the thickness of the fiberglass used. However, the arms are coupled and the length of each arm is approximately equal to ##EQU1## where λ is the wave length of the signal. Feeding arms 18, 20, 22 and 24 in phase quadrature results in a cardiodal pattern in free space with a maximum gain being on axis as shown in FIG. 4. The embodiment shown in FIGS. 1-3 is that of a right-hand circularly polarized antenna. The feed system of the antenna is shown in a block diagram form in FIG. 3 where each of the connectors 26, 28, 30 and 32 is connected to a respective member of impedances 36, 38, 40 and 42. The output at connectors 26 and 32 through their matching networks 36 and 42 are out of phase by 180 degrees. Likewise the outputs at connectors 28 and 30 are delayed from one another by 180 degrees. The combined output of connectors 26, 32 and the combined output of connectors 28 and 30 are delayed from one another by 90 degrees in order to get the output 44. As shown in FIGS. 1 and 2, a radome 50 maybe used around cylinder 12 to make it pressure proof.

FIG. 4 shows a free space pattern which is independent of height, i.e., there is no signal received from the bottom of the antenna. FIG. 5 is a graphical representation of the distribution of the signal when the antenna is placed over a ground plane and mounted in a section of the mast of a periscope which simulates a periscope sticking out of the water and the satellite at various angles above the horizon. Thus FIG. 5 gives a typical pattern above a ground plane. This pattern is almost the same pattern regardless of the position of the antenna above the ground plane within the normal operating range of the periscope.

Briefly stated, a UHF around-a-mast quadrifilled microstrip antenna which includes a cylindrical fiberglass cylinder which has four equispaced metallic strips plated thereon at an angle, preferably an angle of 15 degrees and the inner top and bottom surfaces of the cylinder are metal plated. A coaxial connector is attached to each of the arms and a radome is added for pressure proofing.

Obviously, many modifications and variations of the present invention may become apparent in the light of the above teachings. As an example, the material used for the cylinder and radome can be changed without by its equivalent materials. Furthermore, the metal arms plated on the fiberglass cylinder may be placed at an angle other than 15 degrees for appropriate use. Furthermore, the material of the radome to pressure proof can also be changed by something equivalent thereto. The antenna can be made right-hand of left-hand circularly polarized by positioning the wide arms on the fiberglass cylinder. It is therefore understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3906509 *Mar 11, 1974Sep 16, 1975Duhamel Raymond HCircularly polarized helix and spiral antennas
US4008479 *Nov 3, 1975Feb 15, 1977Chu Associates, Inc.Dual-frequency circularly polarized spiral antenna for satellite navigation
US4204212 *Dec 6, 1978May 20, 1980The United States Of America As Represented By The Secretary Of The ArmyConformal spiral antenna
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4631709 *Jul 13, 1984Dec 23, 1986Bender Roland AFor immersion in water
US4847627 *Sep 8, 1987Jul 11, 1989Lockheed CorporationCompact wave antenna system
US4859107 *Dec 2, 1987Aug 22, 1989Vickers Shipbuilding & Engineering LimitedStructures subject to bending and fatigue loading
US4958162 *Sep 6, 1988Sep 18, 1990Ford Aerospace CorporationNear isotropic circularly polarized antenna
US5134422 *Nov 29, 1988Jul 28, 1992Centre National D'etudes SpatialesHelical type antenna and manufacturing method thereof
US5198831 *Sep 26, 1990Mar 30, 1993501 Pronav International, Inc.Personal positioning satellite navigator with printed quadrifilar helical antenna
US5291211 *Nov 20, 1992Mar 1, 1994Tropper Matthew BA radar antenna system with variable vertical mounting diameter
US5541617 *Jul 7, 1994Jul 30, 1996Connolly; Peter J.Monolithic quadrifilar helix antenna
US5572172 *Aug 9, 1995Nov 5, 1996Qualcomm Incorporated180° power divider for a helix antenna
US5635945 *May 12, 1995Jun 3, 1997Magellan CorporationQuadrifilar helix antenna
US5828348 *Sep 22, 1995Oct 27, 1998Qualcomm IncorporatedDual-band octafilar helix antenna
US5859621 *Feb 21, 1997Jan 12, 1999Symmetricom, Inc.Antenna
US5896113 *Dec 20, 1996Apr 20, 1999Ericsson Inc.Quadrifilar helix antenna systems and methods for broadband operation in separate transmit and receive frequency bands
US5909196 *Dec 20, 1996Jun 1, 1999Ericsson Inc.To provide electrical signals to a receiver/transmit electrical signals
US5920292 *Dec 20, 1996Jul 6, 1999Ericsson Inc.L-band quadrifilar helix antenna
US5945963 *Jun 13, 1996Aug 31, 1999Symmetricom, Inc.Dielectrically loaded antenna and a handheld radio communication unit including such an antenna
US5986620 *Jul 31, 1996Nov 16, 1999Qualcomm IncorporatedDual-band coupled segment helical antenna
US5990847 *Apr 30, 1996Nov 23, 1999Qualcomm IncorporatedCoupled multi-segment helical antenna
US6025816 *Dec 24, 1996Feb 15, 2000Ericsson Inc.Antenna system for dual mode satellite/cellular portable phone
US6181297Dec 3, 1998Jan 30, 2001Symmetricom, Inc.Antenna
US6184844 *Mar 27, 1997Feb 6, 2001Qualcomm IncorporatedDual-band helical antenna
US6229499Nov 5, 1999May 8, 2001Xm Satellite Radio, Inc.Folded helix antenna design
US6278414Jul 31, 1996Aug 21, 2001Qualcomm Inc.Bent-segment helical antenna
US6300917Aug 12, 1999Oct 9, 2001Sarantel LimitedAntenna
US6369776Sep 29, 1999Apr 9, 2002Sarantel LimitedAntenna
US6535179Oct 2, 2001Mar 18, 2003Xm Satellite Radio, Inc.Drooping helix antenna
US6552693Nov 29, 1999Apr 22, 2003Sarantel LimitedAntenna
US6606059 *Aug 28, 2000Aug 12, 2003Intel CorporationAntenna for nomadic wireless modems
US6621458Apr 2, 2002Sep 16, 2003Xm Satellite Radio, Inc.Combination linearly polarized and quadrifilar antenna sharing a common ground plane
US6690336Jun 15, 1999Feb 10, 2004Symmetricom, Inc.Antenna
US8106846May 1, 2009Jan 31, 2012Applied Wireless Identifications Group, Inc.Compact circular polarized antenna
US8618998Jul 21, 2009Dec 31, 2013Applied Wireless Identifications Group, Inc.Compact circular polarized antenna with cavity for additional devices
EP0135742A1 *Aug 3, 1984Apr 3, 1985Messerschmitt-Bölkow-Blohm Gesellschaft mit beschränkter HaftungOmnidirectional antenna
EP0320404A1 *Dec 9, 1988Jun 14, 1989Centre National D'etudes SpatialesHelix-type antenna and its manufacturing process
WO1991015621A1 *Apr 3, 1991Oct 17, 1991Bentley Harris Mfg CoAntenna structure and method of making same
WO2012100859A1 *Nov 25, 2011Aug 2, 2012Gabler Maschinenbau GmbhAntenna for a submarine
Classifications
U.S. Classification343/700.0MS, 343/895, 343/709
International ClassificationH01Q1/38, H01Q21/26, H01Q21/20, H01Q1/34
Cooperative ClassificationH01Q21/26, H01Q21/205, H01Q1/38, H01Q1/34
European ClassificationH01Q21/26, H01Q1/34, H01Q1/38, H01Q21/20B
Legal Events
DateCodeEventDescription
Oct 27, 1980ASAssignment
Owner name: UNITED STATES OF AMERICA THE, AS REPRESENTED BY TH
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HARRIS ELEANOR S.;REEL/FRAME:003825/0970
Effective date: 19800919